Post-Marketing Surveillance and Pharmacovigilance: Regulatory Responsibilities and Emerging Challenges

- Pharmacovigilance and post-marketing surveillance form the foundation of global drug safety oversight, ensuring that medicinal products remain effective and safe throughout their lifecycle. Preapproval clinical trials are limited by small sample sizes, controlled settings, and short follow-up periods, making real world monitoring essential to identify rare, delayed, or population-specific adverse drug reactions. International bodies such as the WHO, ICH, FDA, EMA, and CDSCO have established comprehensive regulatory frameworks that support systematic signal detection, benefit risk assessment, and timely regulatory interventions. Post marketing tools including spontaneous reporting systems, active surveillance programs, electronic health records, patient registries, and digital reporting platforms enable continuous safety monitoring across diverse populations. Technological advancements, particularly artificial intelligence, real world evidence, pharmacogenomics, and digital health innovations, have shifted pharmacovigilance toward proactive and predictive safety management. Despite this progress, challenges persist, including underreporting, data inconsistencies, global regulatory variability, and ethical concerns related to privacy and transparency. Historical and contemporary case studies such as the thalidomide disaster, Vioxx withdrawal, and COVID-19 vaccine surveillance highlight both achievements and remaining gaps in global PV systems. Strengthening patient participation, harmonizing international practices, and investing in digital infrastructure remain essential for building a responsive, transparent, and patient-centered pharmacovigilance ecosystem.